(8.D.2.5) AGCAttackRelease
Overview
Multi-channel envelope detector with programmable attack and release times
Discussion
Envelope detector used in dynamics processor. The module accepts an N-channel buffer of amplitude and produces an output buffer the same size as the input. An envelope detector is applied to the input that has programmable attack and release times. The attack time applies when the current input value is larger than the state of the envelope detector. Similarly, the release time applies when the current input value is smaller than the state of the envelope detector.
Type Definition
typedef struct _ModuleAGCAttackRelease
{
ModuleInstanceDescriptor instance; // Common Audio Weaver module instance structure
FLOAT32 attackTime; // Speed at which the detector reacts to increasing levels.
FLOAT32 releaseTime; // Speed at which the detector reacts to decreasing levels.
FLOAT32 attackCoeff; // Internal coefficient realizing the attack time.
FLOAT32 releaseCoeff; // Internal coefficient realizing the release time.
FLOAT32* envStates; // Vector of sample-by-sample states of the envelope detectors; each column is the state for a channel.
} ModuleAGCAttackReleaseClass;
Variables
Properties
Name | Type | Usage | isHidden | Default value | Range | Units |
attackTime | float | parameter | 0 | 2 | 0.01:1000 | msec |
releaseTime | float | parameter | 0 | 100 | 0.01:1000 | msec |
attackCoeff | float | derived | 1 | 0.01036 | Unrestricted | Â |
releaseCoeff | float | derived | 1 | 0.0002083 | Unrestricted | Â |
envStates | float* | state | 1 | [1 x 1] | Unrestricted | Â |
Pins
Input Pins
Name: in
Description: audio input
Data type: float
Channel range: Unrestricted
Block size range: Unrestricted
Sample rate range: Unrestricted
Complex support: Real
Output Pins
Name: out
Description: audio output
Data type: float
MATLAB Usage
File Name: agc_attack_release_module.m
M=agc_attack_release_module(NAME)
Envelope detector with programmable attack and release time constants.
Arguments:
NAME - name of the module.
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